Large scale poultry farming involves raising vast numbers of birds, typically in a flock of thousands, living communally in fixed structure shelters, (“houses”). The flock remains together and does not move from a single house during nearly its entire growing cycle extending from the age of young chicks until harvesting as adults. Feeding the animals is, of course, a critical aspect of the operation and it can involve the transfer of very large quantities of food.
The industry typically utilizes granular feed which the grower purchases in bulk from a feed supplier. The feed is delivered to the farm and is deposited by the supplier into one or more on-site storage bins local to the poultry houses. From time to time, as feed is dispensed to the birds from the local bins, it is replenished by the supplier. During the growing cycle, the birds require different feed formulations that correspond with their stage of maturity and further depend on other factors determined by the grower. Accordingly, the composition of the feed delivered by the supplier will change during the growing cycle.
Normally at harvest time, mature birds are removed to a processing plant leaving the formerly occupied house vacant. The house is then prepared for occupancy by a new crop of young birds. Frequently there is a residual quantity of adult formulation feed in the bins of the recently vacated houses. This feed is not suitable for the incoming chicks. The grower calls on the supplier to remove residual food from the bins. The grower gets a refund for returned feed and the bins are emptied so they may be re-stocked appropriately.
Feed is usually transported in bulk transfer cargo trailers equipped with large tanks and pulled by standard over-the-road tractors. The supplier ordinarily maintains a fleet of tractor-trailer combinations of size appropriate for delivery of feed to the grower-customers. Picking up residual feed from vacated poultry houses is a necessary but usually smaller volume aspect of the supplier's business. Normally only a small portion of the supplier's fleet consists of specialized tractors and trailers dedicated to residual feed pick up service.
Traditionally trailers of the pick-up fleet basically have a tank for accepting the residual feed, a pick-up conveyor system for loading the residual feed to the top of the tank and another discharge conveyor system for unloading the feed from the bottom of the tank. The trailer has no loading or unloading drive power source of its own to motivate the pickup and discharge conveyor systems.
A specially equipped tractor is dedicated to pick-up trailer service. In addition to its normal operating equipment, the special tractor has a blower to provide pneumatic conveying air for the pick-up conveyor system of the trailer. This tractor also has an added mechanical drive for the blower. The mechanical drive takes power from the drive transmission of the tractor's main engine. Thus the step of removing residual feed calls for bringing a trailer to the site with a specially equipped tractor, running the tractor engine to operate the blower, and transferring the residual feed from the bin to the trailer tank with the pneumatic conveyor using air provided by the tractor-mounted blower.
This conventional feed pick-up system has commercially significant drawbacks. Firstly, existing tractors with pick-up capability are more expensive to outfit than standard tractors. The blower must be driven by the mechanical link to the tractor transmission. Therefore at least one tractor of the fleet must have a transmission specially equipped with the mechanical link. This can contributes substantially to the cost of the tractor because the mechanical link is an specially added tractor feature. Additionally, the supplier has to inventory special replacement parts and to undertake specialized maintenance procedures to keep pick-up service capable tractors in good repair.
Secondly, conventional feed pick-up vehicles create certain logistical problems for the supplier. Feed suppliers prefer to have a low number of specially equipped pick-up service tractors. This is because these tractors are more expensive than standard tractors and the relatively low volume of feed pick-up service compared to normal feed delivery service does not justify having more than a few, minimally essential units in the fleet. However, pick-ups can occur at difficult to predict times and must meet the needs of the growers' schedules. Consequently the supplier prefers to have a pick-up tractor/trailer combination available at nearly all times. The high availability is frequently satisfied by dedicating at least one tractor/trailer combination exclusively to residual feed pick-up despite the low volume of use. This can lead to suppliers overextending the time in service of the pick-up capable tractors which tends to induce more frequent unexpected breakdowns of aging equipment. In short, it is logistically difficult and relatively expensive for the feed supplier to maintain its part of the fleet of vehicles exclusively dedicated to residual feed pick-up service.
Another flaw of many conventional feed pick-up fleet systems is that a rubber belt coupling is commonly included in the link between the tractor engine transmission and the blower. The coupling produces a stepped up shaft rotation speed to properly operate the blower. Accidentally from time to time either mechanical failure or operator error can cause the pneumatic conveyor transfer lines on the pick-up trailer to occlude with feed particles. The tractor transmission will continue to turn with the blower dead-headed against the plug. Unless the operator reacts quickly, damage to the blower can result. Usually the rubber belt overheats and breaks. The cost of the broken belt is not trivial, but perhaps more problematic is the expense due to time required to access and replace the broken belt with a new one.
It is desirable to have a residual feed pick-up fleet system that uses more, if not all, standardized mechanical components and is logistically more flexible to operate. A system in which the supplier can use any unit of its normal tractor fleet to operate a feed pick-up trailer would be a great productivity advantage. It is also desired to have a system that has fewer special parts to stock and requires less specially trained mechanics to maintain in good operating condition. A system that is less costly to purchase, maintain, repair and operate than conventional residual feed pick-up subsystems is much desired.